In the art, there have been a variety of cleaning devices capable of collecting either dry material (such as debris), wet material (such as medical spills or animal feces) or both.
As an example, U.S. Pat. No. 4,152,080 discloses an animal waste cleaning device including collection means which can be provided in various sizes to accommodate the collection of different sized pet waste. However, this device exposes operators to the waste and associated noxious fumes as some handling of the waste by the operators is required.
Further, tank-type vacuum cleaners used for suctioning dry material and liquids are known in the art. However, it is difficult to empty liquids from such tank-type vacuum cleaners. When the receptacle is full, the receptacle is removed and the contents are dumped out. If the receptacle is used to collect liquid material, the container may be very heavy so that lifting the tank to pour the contents into a sink or the like is difficult. Even tilting the container to pour the contents into a floor drain may be unwieldy when the liquid level in the receptacle is high.
There have been a number of other proposed solutions to try to help operators clean up dry or wet waste easily. For example, U.S. Pat. No. 6,079,076 describes vacuum cleaners having filter bags for capturing debris and wet material which sit inside the tank. However, it is difficult to empty liquid from such receptacles, and the filter bags may be costly.
Yet another method of expelling waste is described in U.S. Pat. No. 6,009,596 which describes vacuum cleaners having a pump impeller to expel liquid to empty the liquid easily from a tank used for collecting material. However, this device also suffers from difficulties emptying the collected waste, especially when the waste is in the form of a sludge.